Modelling of microorganisms capture on magnetic carrier particles

Immunomagnetic separation (IMS) is a technique used in the detection of pathogenic microorganisms from food and environmental samples. Current IMS methods are insensitive due to the small sample sizes analysed. A stochastic model is described which estimates the time of collision between a small number of pathogenic microorganisms and superparamagnetic carrier microparticles within an aqueous suspension. The IMS system parameters which are varied in the model include: the diameter of the carrier particles, their volume concentration in suspension, the fraction of magnetic phase within the composite material of the particles and the magnetic field intensity and gradient. The data obtained will be used to help design magnetic separation systems to capture pathogenic microorganisms from large volume samples (approx. 250 ml).